Prior art couplers have typically been held in place by a bulkhead holder which can be threadably adjusted in position using lock nuts to vary the distance from a power coupling head to an electromagnetic field generating source. The electrical signal is passed through the center of the bulkhead holder in much the fashion of a shielded cable with the threads being effectively at ground potential. At the end remote from the power head, a shielded electrical cable is typically attached to provide electrical signals to a receiving circuit. While a lock nut of some type is used to prevent any further movement of the coupler, the design has been such that the power coupling head was allowed considerable freedom of movement side-to-side. This movement of the power coupling head through the field can cause a modulation or distortion of the signal that is transmitted from the resonator or oscillator. This distortion must be accounted for or allowed for in the receiving circuitry through the use of filtering or other means of ignoring or eliminating the distortion of the signal.
The design of cabling for the frequencies of interest in one embodiment of the inventive concept is such that the shielding renders it relatively inflexible. Thus, if space is at a premium, there may not be enough room to make the bends to connect from the prior art power coupler to the receiving electrical circuit. This problem may be exacerbated when the electrical circuit is required to be at right angles to the power coupler. Further there is an insertion loss in the signal as it is passed through each connector and the possibility of signal distorting reflections occurs with each discontinuity such as a connector.